Biodiversity

Question 1

3.1.1 recognise that biodiversity includes the diversity of species and ecosystems

What is biodiversity?

Answer 1

Biodiversity is the variety of life, and includes all living things (plants, animals, and micro-organisms) and their unique characteristics.

It can mean the variety of habitats, living communities and ecological processes in an ecosystem.

It can mean the diversity of genetic characteristics within a species.

It can mean the variety of species in a given area.

Question 2

Syllabus objective:
Recognise that biodiversity includes the diversity of species and ecosystems

What are the three types of biodiversity?

Answer 2

Genetic diversity is the diversity of genes within a species.
Species diversity is the diversity among species in an ecosystem.
Ecosystem diversity os the diversity of a habitat in a given unit area.

Question 3

Why is biodiversity important?

Answer 3

Biodiversity Provides the Food We Eat.
Biodiversity Keeps Us Healthy.
Biodiversity Supports our Ecosystem.
Biodiversity Safeguards Nature As We Know It.
Biodiversity Helps Our Economy Thrive.
Biodiversity Can Potentially Provide A Solution To Climate Change.
Biodiversity Preserves Our Cultural Ethics and Aesthetics.

Question 4

How does biodiversity increase ecosystem stability?

Answer 4

Ecosystems depend on the combined contributions of the individual organisms within them. The loss of any species can prevent that ecosystem from operating the way it should. An ecosystem with a high level of biodiversity is more resistant to environmental change. Greater biodiversity in ecosystems, species, and individuals leads to greater stability. For example, species with high genetic diversity and many populations that are adapted to a wide variety of conditions are more likely to be able to overcome weather disturbances, disease, and climate change.

Question 5

3.1.3 Use species diversity indices, species interactions, and abiotic factors to compare ecosystems across spatial and temporal scales.

Explain species interactions.

Answer 5

Species do not live in isolation. Within ecological communities, these interactions form the basis of nutrient cycling and food webs. Understanding these interactions help in understanding an organism’s abundance and distribution across spatial (distance between habitats) and temporal (habitat lifespan relative to generation time of organism) scales.

Question 6

3.1.3 Use species diversity indices, species interactions, and abiotic factors to compare ecosystems across spatial and temporal scales.

Comparing ecosystem using predation.

Answer 6

Predator-prey interactions affect species that are present, plant densities in an area, behaviour, and feeding habits of prey animals, local biodiversity and invasion of plant and animals into an area. Comparing prey and predation populations shows fluctuating waves in population density over time. In the beginning there is equal population density. Here the predator population is at its lowest, trough, and prey population starts to rise. At the peak of the prey wave the predator population starts to rise due to an increased availiability of food. Eventually the prey population will decline because of increased predation. Finally as a result of the prey decline the predator population will respond by decreasing.

Question 7

3.1.3 Use species diversity indices, species interactions, and abiotic factors to compare ecosystems across spatial and temporal scales

Contrast intraspecific and interspecific competition.

Answer 7

Intraspecific competition is rivalry between individuals of the same species for limited resources. As they share an ecological niche, they have the same requirements for life. Can lead to fighting, injury, death, or exclusion from group, but generally does not impact population as a whole. Interspecific between individuals from different species for resources. Compete for one or more resources required by both species. For example, different species of birds mya nest in the same area, but will not compete for mates. Can lead to fighting, injury, death and may also reduce population size of a species, including possible elimination of the species from the ecosystem.

Question 8

3.1.3 Use species diversity indices, species interactions, and abiotic factors to compare ecosystems across spatial and temporal scales

Comparing organisms by disease.

Answer 8

Infectious disease-causing pathogens have the ability to reduce numbers significantly when population density increases. Individuals living in higher density areas and sharing resources have higher disease transmission rates. This can lead to higher infection rates and higher mortality can reduce population size over time.

Question 9

3.1.3 Use species diversity indices, species interactions, and abiotic factors to compare ecosystems across spatial and temporal scales

Calculating population density.

Answer 9

Population density is the number of individuals that live in a defined area. Population density is a measuremnet of the number o individuals living in a defined space.

number of individuals/ area (units^2) = population density

Question 10

3.1.3 Use species diversity indices, species interactions, and abiotic factors to compare ecosystems across spatial and temporal scales

Comparing ecosystems using abiotic factors.

Answer 10

Abiotuc factors are non-living components of an ecosystem that organisms must exploit and adapt to in order to survive and reproduce. They influence the ability of a species to survive based on the tolerance range for factors such as temperature, sunlight and water availability.

Question 11

3.1.3 Use species diversity indices, species interactions, and abiotic factors to compare ecosystems across spatial and temporal scales

How does temperature affect organisms?

Answer 11

Determine geographic location where speices can survive and maintain homeostasis (is a self-regulating process by which biological systems maintain stability while adjusting to changing external conditions)
Physiological and behaviour adaptations allow access to wider temp range

Question 12

3.1.3 Use species diversity indices, species interactions, and abiotic factors to compare ecosystems across spatial and temporal scales

How does wind affect organisms?

Answer 12

Wind strength, speed and direction impact where species can survive.
Plants may have stronger root systems to survive high wind speeds and may rely on strong winds to distribute speed.

Question 13

3.1.3 Use species diversity indices, species interactions, and abiotic factors to compare ecosystems across spatial and temporal scales

How does water availability affect organisms?

Answer 13

Water is essential for survival for all living things and its distribution determines distribution and behaviour of all species.

Question 14

3.1.3 Use species diversity indices, species interactions, and abiotic factors to compare ecosystems across spatial and temporal scales

How does sunlight organisms?

Answer 14

Light intensity impacts photosynthetic organisms and subsequently those species that rely on them as a food source. Reduced light intensity limits rate of photosynthesis for these organisms.

Question 15

3.1.3 Use species diversity indices, species interactions, and abiotic factors to compare ecosystems across spatial and temporal scales

Describe the substrate factors that affect organisms.

Answer 15

pH level can affect groth rate of plants, bacteria, and soil-dwelling animals
nutrient content are essential for plant growth, different species require different combinations of nutrients which determines how well plants can grow in an area
particle size- plants with deep root systems may prefer softer soils
composition- includes water drainage, and make up of sand, clay, silt
salinity- amount of salt can impact plant’s ability to obtain water via osmosis

Question 16

3.1.3 Use species diversity indices, species interactions, and abiotic factors to compare ecosystems across spatial and temporal scales

How does size/depth of an area affect organisms?

Answer 16

Size of an area may impact the nuber of species and popukation size of each species in a community.
Depth of an area can change the factors such as light availability, and pressure (which increases depth). Organisms capable of surviving at the bottom of oceans have adpatations to cope with high pressure and have alternative energy sources.

Question 17

3.1.4 Explain how environmental factors limit the distribution and abundance of species in an ecosystem.

Explain factors affecting the distribution of species.

Answer 17

The distribution of species is a measure of the geograpical area where the species is found. Species are often capable of physically moving between ecosystems. Barriers to wider distributions are usually related to changes in temperature, water, precipitation, water, or soil.

Question 18

3.1.4 Explain how environmental factors limit the distribution and abundance of species in an ecosystem.

Explain the abundance of species.

Answer 18

The abundance of a species is a measure of the size of the population in a species area at a given time. Relative abundance compares the abundance of a species to the abundance of other species living in the same area. It can fluctuate over time as biotic and abiotic factors change. It is a useful meaure when trying to determine the most dominant or rare species in different ecosystems or at different times.

Question 19

3.1.4 Explain how environmental factors limit the distribution and abundance of species in an ecosystem.

How do environmental factors limit distribution and abundance?

Answer 19

Biotic and abiotic factors of an environment determine how and if a particular species can thrive in that location. Conditions outside the tolerance range for a species will limit its distribution. If a particular species exists in an area at the upper limit of its tolerance range, it may continue to survive, but with a reduced population. When organisms are stressed, their reproductive rate may slow or stop, or they may die. These factors may reduce the population in these areas. For example, the periodic intrusion of seawater into salt marshes may constitute a disturbance that prevents most species from becoming abundant other than a few species that are able to cope with the periodic exposure to salt water. As a result, there is a large disparity in the abundance of species from the species-poor communities found in salt marshes.